Biomass hydrolysis

Abstract

High-yielding method for chemical hydrolysis of lignocellulose into monosaccharides. The process of the invention can additionally be applied to cellulose, xylan and related biomass polysaccharides, such as galactan, mannan, or arabinan. The method is employed for hydrolysis of a biomass polysaccharide substrate. The process is carried out in an ionic liquid in which cellulose is soluble in the presence of catalytic acid at a temperature sufficiently high to initiate hydrolysis. Water is added to the reaction mixture after initiation of hydrolysis at a rate controlled to avoid precipitation yet avoid undesired sugar dehydration products such ad HMF. Hydrolysis product is useful as feedstock for fermentations including fermentation processes for ethanol, butanol and other fuels.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. provisional application 61 / 222,397, filed Jul. 1, 2009 which application is incorporated by reference in its entirety herein.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]This invention was made with United States government support awarded by the following agencies: DOE DE-FC02-07ER64494. The United States government has certain rights in this invention.BACKGROUND OF THE INVENTION[0003]Abundant plant biomass could become a sustainable source of fuels and chemicals. Unlocking this potential requires the economical conversion of recalcitrant lignocellulose into useful intermediates, such as sugars. We report a high-yielding process for the chemical hydrolysis of lignocellulose into monosaccharides. Adding water gradually to a chloride ionic liquid containing catalytic acid leads to a nearly 90% yield of glucose from cellulose and 70-80% yield of sugars from untreated corn s...

AI Technical Summary

Benefits of technology

[0035]The ionic liquid chloride salt dissolves cellulose and is believed to facilitate enhanced yield of glucose. Cellulose is introduced into the ionic liquid and vigorously stirred or mixed to aid dissolution. Optionally, the cellulose is stirred in the ionic liquid for at least an hour prior to adding acid and initiating the reaction. Enhanced glucose yield can be obtained if the cellulose is mixed with the ionic liquid for up to 3, up to 6 or up to 9 hours prior to initiation of reaction. This premixing of the ionic liquid with lignocellulose can be performed at ambient temperature or at a temperature above ambient up to 140 C, dependent upon the melting or softening point of the ionic liquid. The ionic liquid should be liquid or at least softened (so that it can be mixed). More specifically, the premixing can be performed at reaction temperature, specifically at a temperature between 70 and 140° C.

[0036]The ionic liquid chloride salt decrystallizes lign

Problems solved by technology

The challenge for chemists is to access these polymers and convert them into fuels and chemical building blocks.

Deriving sugars from this heterogeneous feedstock requires both physical and chemical disruption.

Nonetheless, the costs of both pretreatment and enzymes (estimated to be as much as one-third of the cost of ethanol production from cellulose, [12]) and low rates of hydrolysis are potential drawbacks to enzymatic hydrolysis.

Concentrated acid hydrolysis met

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